I have a 2009 335i Automatic. Purchased about 43k in March of this year. Modifications before this all began:
Cobb AccessPort
VRSF downpipes
ETS 5" FMIC
CPe DCI
BMT Oil Catch Can

The reason for the LSD is the area I live in(Cincinnati) is very hilly. Lots of tight turns and frequent change in grades, so the lack of an LSD was readily apparent even on just some drives home from work. I wouldn't classify it as necessary for daily driving, but I noticed it wasn't there. I'm uncertain if I plan on occasionally tracking this car next year or not, but I do like the occasional spirited drive and I wanted to get a LSD to help with the traction.

The decision for the OS Giken is a personal one and I honestly can't tell you which is right for you. I purchased the TCD model as I wanted to make sure it was as quiet as possible as this is still my daily driver.

So the purchase:
I have friends who have a Subaru oriented shop(Turn In Concepts) that I always planned on having do the install. One of the owners and the lead mechanic had a 335 and had done quite a bit of work on them previously and they're pretty well experienced with differentials. He actually knows someone at OS Giken and offered to setup an account with them to get the part, but suggested I see if someone had the part first already, as it may take a week or so to get it all setup.

I reached out to VAC Motorsports. I actually ordered it online. Their website asks for your VIN, i assume to verify the correct part is ordered. I provided that and placed the order. Then I realized I forgot to order the diff fluids. So i called back to ask if they could add it. I ended up talking to someone in their service department, who advised to just order it separately and they'd combine the products and refund the shipping difference. He began to ask me some questions about my application and basically queried about the state of my stock ring gear. We confirmed(as i had already verified) that my ring gear is bolted. He asked about who was installing it and other questions. All of which reaffirmed my feeling that they wanted to make sure I was making the right purchase and had all my ducks lined up. Was feeling pretty good.

About 4-5 days later, I noticed my order was still "pending" and had not charged against my card. No one had contacted me either. I called in and was told that Chris would have to call me back. Eventually I got a call from Chris, who told me that my diff was not in stock. He'd apparently been trying to locate one from another US vendor since OS Giken USA had none in stock currently. Not sure why he wouldn't have told me this the day after i ordered? Why make me wait those days without giving me a heads up?

So he agrees to call me Monday and tell me what the status is. No call on Monday. Tuesday he calls and says he can get it from Japan but it's gonna take about 14 days to get it in and get it to me.

That's ok, as I'm about to travel overseas in a week. I'll be gone for 3 weeks and am leaving my car at the shop. So we'll just ship it to my shop's address and they'll still have plenty of time to install it. Unfortunately, he said he couldn't ship it there if I paid by credit card. I'd have to pay by check. Fine. I send a check 2 days later, which they receive, about 9 days before the diff is scheduled for delivery at my shop's location.

While I'm overseas i check in on the delivery date. No diff. Finally, two days later, it arrives. He'd quoted me the date it'd arrive at VAC, not at the shop. Argh, ok, moving on. Bad news. The shop opens up my diff, looks down at the new one, realizes, it's not gonna fit.

He sent me a diff for a large pumpkin application, not a small pumpkin. Ugh. My shop had already reached out to VAC directly before they told me this. Arrangements had been made to get the replacement diff shipped out and it'd be there by the following Tuesday. They'll ship the other one back. So annoying, but we're still good.

Tuesday comes. No diff. Wednesday, no diff. Thursday, i reach out and am told that "The diff you need is not in stock and we'll have to order it from overseas". What? How did you quote the shop that the replacement would be there next tuesday if there wasn't even one in stock? Haven't we been down this road before? Are you kidding me?

I'm beginning to lose it. I don't mind mistakes. They happen, but this was getting ridiculous. Now, the replacement is NOT going to make it before I get back from my trip. The shop cannot leave my car on a lift any longer. They must reassemble the stock diff. That's 4 hours of labor that I owe them for with no benefit. Trust me, TiC felt pretty crappy about it, but they did the work so they need to be paid. Plus the cost of fluid, seals....ugh.

So luckily, the next time I call, Chris is no longer there. I'm told Mike has taken over his accounts. I calmly explained the long list of issues I've had. I explain my lack of faith at this point. Mike listened to the entire story. We started first by trying to figure out where I was at. We couldn't verify that there was actually a part coming in for me, or if there was, was it the correct part? He did verify that the part they listed as me needing, appeared to be correct. But that's not what was ordered the first time from OS Giken. So first, Mike spent a few days verifying the part with OS Giken. Then determining availability.

After telling OS Giken about this, I'm not sure of the details, but they decided to express ship the parts from Japan to their US location for assembly. They gave me an estimate for arrival and it did arrive that day but was released from customs a few days later. It was shipped directly from OS Giken to my installers location shortly after.

It took me a few weeks to arrange time again to have the install performed. I had it completed last week and it went flawlessly this time.

I called Mike to notify him that everything was working and to discuss the events. VAC made me a very fair offer to compensate for the time/money that I spent. It didn't cover every $ of expense, but that's ok, because there's a certain degree of "pay to play" in this market. I was very content with their offer and happy that it required no argueing or pushing on my side.

The experience started off pretty bad, but I honestly think it was directly related to one particular employee, not the company as a whole. Mike took care of the issue and made me a satisfied customer, despite the rocky beginnings.

The LSD itself is amazing. I've yet to finish the 500 miles before the first fluid change, which I'm treating like a break in period, but I can already feel the difference on some of the roads i drive regularly. Even on the occasional on-ramp it's a little noticeable.

I'll do a more thorough review when I have more time to push it, but it may be hard with the winter rolling in and my tires getting harder and harder.

I have a 2009 335i Automatic. Purchased about 43k in March of this year. Modifications before this all began:
Cobb AccessPort
VRSF downpipes
ETS 5" FMIC
CPe DCI
BMT Oil Catch Can

The reason for the LSD is the area I live in(Cincinnati) is very hilly. Lots of tight turns and frequent change in grades, so the lack of an LSD was readily apparent even on just some drives home from work. I wouldn't classify it as necessary for daily driving, but I noticed it wasn't there. I'm uncertain if I plan on occasionally tracking this car next year or not, but I do like the occasional spirited drive and I wanted to get a LSD to help with the traction.

The decision for the OS Giken is a personal one and I honestly can't tell you which is right for you. I purchased the TCD model as I wanted to make sure it was as quiet as possible as this is still my daily driver.

So the purchase:
I have friends who have a Subaru oriented shop(Turn In Concepts) that I always planned on having do the install. One of the owners and the lead mechanic had a 335 and had done quite a bit of work on them previously and they're pretty well experienced with differentials. He actually knows someone at OS Giken and offered to setup an account with them to get the part, but suggested I see if someone had the part first already, as it may take a week or so to get it all setup.

I reached out to VAC Motorsports. I actually ordered it online. Their website asks for your VIN, i assume to verify the correct part is ordered. I provided that and placed the order. Then I realized I forgot to order the diff fluids. So i called back to ask if they could add it. I ended up talking to someone in their service department, who advised to just order it separately and they'd combine the products and refund the shipping difference. He began to ask me some questions about my application and basically queried about the state of my stock ring gear. We confirmed(as i had already verified) that my ring gear is bolted. He asked about who was installing it and other questions. All of which reaffirmed my feeling that they wanted to make sure I was making the right purchase and had all my ducks lined up. Was feeling pretty good.

About 4-5 days later, I noticed my order was still "pending" and had not charged against my card. No one had contacted me either. I called in and was told that Chris would have to call me back. Eventually I got a call from Chris, who told me that my diff was not in stock. He'd apparently been trying to locate one from another US vendor since OS Giken USA had none in stock currently. Not sure why he wouldn't have told me this the day after i ordered? Why make me wait those days without giving me a heads up?

So he agrees to call me Monday and tell me what the status is. No call on Monday. Tuesday he calls and says he can get it from Japan but it's gonna take about 14 days to get it in and get it to me.

That's ok, as I'm about to travel overseas in a week. I'll be gone for 3 weeks and am leaving my car at the shop. So we'll just ship it to my shop's address and they'll still have plenty of time to install it. Unfortunately, he said he couldn't ship it there if I paid by credit card. I'd have to pay by check. Fine. I send a check 2 days later, which they receive, about 9 days before the diff is scheduled for delivery at my shop's location.

While I'm overseas i check in on the delivery date. No diff. Finally, two days later, it arrives. He'd quoted me the date it'd arrive at VAC, not at the shop. Argh, ok, moving on. Bad news. The shop opens up my diff, looks down at the new one, realizes, it's not gonna fit.

He sent me a diff for a large pumpkin application, not a small pumpkin. Ugh. My shop had already reached out to VAC directly before they told me this. Arrangements had been made to get the replacement diff shipped out and it'd be there by the following Tuesday. They'll ship the other one back. So annoying, but we're still good.

Tuesday comes. No diff. Wednesday, no diff. Thursday, i reach out and am told that "The diff you need is not in stock and we'll have to order it from overseas". What? How did you quote the shop that the replacement would be there next tuesday if there wasn't even one in stock? Haven't we been down this road before? Are you kidding me?

I'm beginning to lose it. I don't mind mistakes. They happen, but this was getting ridiculous. Now, the replacement is NOT going to make it before I get back from my trip. The shop cannot leave my car on a lift any longer. They must reassemble the stock diff. That's 4 hours of labor that I owe them for with no benefit. Trust me, TiC felt pretty crappy about it, but they did the work so they need to be paid. Plus the cost of fluid, seals....ugh.

So luckily, the next time I call, Chris is no longer there. I'm told Mike has taken over his accounts. I calmly explained the long list of issues I've had. I explain my lack of faith at this point. Mike listened to the entire story. We started first by trying to figure out where I was at. We couldn't verify that there was actually a part coming in for me, or if there was, was it the correct part? He did verify that the part they listed as me needing, appeared to be correct. But that's not what was ordered the first time from OS Giken. So first, Mike spent a few days verifying the part with OS Giken. Then determining availability.

After telling OS Giken about this, I'm not sure of the details, but they decided to express ship the parts from Japan to their US location for assembly. They gave me an estimate for arrival and it did arrive that day but was released from customs a few days later. It was shipped directly from OS Giken to my installers location shortly after.

It took me a few weeks to arrange time again to have the install performed. I had it completed last week and it went flawlessly this time.

I called Mike to notify him that everything was working and to discuss the events. VAC made me a very fair offer to compensate for the time/money that I spent. It didn't cover every $ of expense, but that's ok, because there's a certain degree of "pay to play" in this market. I was very content with their offer and happy that it required no argueing or pushing on my side.

The experience started off pretty bad, but I honestly think it was directly related to one particular employee, not the company as a whole. Mike took care of the issue and made me a satisfied customer, despite the rocky beginnings.

The LSD itself is amazing. I've yet to finish the 500 miles before the first fluid change, which I'm treating like a break in period, but I can already feel the difference on some of the roads i drive regularly. Even on the occasional on-ramp it's a little noticeable.

I'll do a more thorough review when I have more time to push it, but it may be hard with the winter rolling in and my tires getting harder and harder.

Nice to know it was not a VAC Motorsport issue all around as I have been eyeing the same OS Giken LSD or the Quaife LSD from those guys. You need to go out and drive that sucker so you can get more miles and break her in. Let us know. Curious if the added expense is worth it for the OS Giken vs Quaife one. May I ask why you chose this one instead of the Quaife that most seem to choose?

Nice to know it was not a VAC Motorsport issue all around as I have been eyeing the same OS Giken LSD or the Quaife LSD from those guys. You need to go out and drive that sucker so you can get more miles and break her in. Let us know. Curious if the added expense is worth it for the OS Giken vs Quaife one. May I ask why you chose this one instead of the Quaife that most seem to choose?

In my area, I drive on a lot of tight turns, hilly roads, where the deceleration option was important. Partly, I just had a better feeling for the reputation of OS Giken. Not at all any type of slam on Quaife. However, while the Quaife is cheaper and absolutely sufficient for many, in my location, I have a lot of roads that are older and bumpy and the deceleration lockup would matter. To most, I imagine it wouldn't.

This is the first I've heard about deceleration lockup.....does the Quaife not lock on deceleration? I would be quite bummed to put one in and find that out!

Feel free to point me at threads or tell me to search (that's my next step). Also just wanted to say hi, I'm right down the road from you in Lexington.

Hello neighbor!

The Quaifes don't lock on deceleration(torque biasing diffs can't due to how they work). I'm honestly not sure that's a big deal for many people in a street car. It really depends on the type of road you're driving on and your driving style from how I understand it. That was not my sole reason for choosing OS Giken. While this one was more expensive, I just am a bigger fan of the clutch style vs torque biasing. Again, probably personal preference more than anything.

I did a LOT of research on their implementations on other makes as well before deciding. To get an overall feel for how they are perceived in many situations. It's not uncommon for people with serious track cars to give them a more negative review, but not because they are weak or subject to failure really, but more so because they don't think they operate in the optimum configuration for that venue. Which, is sort of a plus for me, as even if I do track this car, it'll never be a track-dedicated car. It'll always at least be a weekend driver, so street performance was my primary goal. Reliability doesn't seem to be much of an issue with most of the major brands though.

Quote:

Originally Posted by vasillalov

tullnd,

What locking percentage did you choose for your TCD? OSGiken will be my next purchase so I am trying to collect as much feedback as I can.

Undoubtedly, this is the best diff we can get for our cars.

I didn't choose percentages. The Superlock TCD is a set configuration from OS Giken. I imagine it can be customized. I'm not tracking my car so I don't need it tweaked to that degree...and honestly, since all the variables that are involved from diff to diff, I don't think you could get it "just right" on the first try. One diff at certain percentages would never really match another brand/model at the same "percentages". That's more of something to do as you continually evaluate the needs of a racing application in my opinion, but everyone has different feelings on that.

So far, I feel like this one has not shown any over aggressive tendencies for my daily driving that I'm primarily using it for.